Congress has maintained significant interest in Mexico, an ally and top trade partner. In recent decades, U.S.-Mexican relations have been strengthened through cooperative management of the 2,000-mile border, the North American Free Trade Agreement (NAFTA), and security cooperation under the Mérida Initiative. Relations have recently been tested, however, by President Donald J. Trump's shifts in U.S. immigration and trade policies. President Enrique Peña Nieto of the Institutional Revolutionary Party (PRI) is in the final year of his six-year term. During 2013, Peña Nieto shepherded significant structural reforms through the Mexican Congress, including a historic energy reform that opened Mexico's energy market to foreign investment. He has since struggled to implement some of those reforms, and to address human rights abuses and corruption. Homicides surpassed historic levels in 2017, hurting Peña Nieto's already relatively low approval ratings. The possibility of a U.S. withdrawal from NAFTA may have hindered investment, growth, and consumer confidence. Political attention in Mexico is increasingly focused on presidential and legislative elections scheduled for July 1, 2018. Andrés Manuel López Obrador, the leftist populist leader of the National Regeneration Movement (MORENA) party, leads among presumptive candidates. Others include José Antonio Meade (former finance minister) for the PRI; Ricardo Anaya (former president of the conservative National Action Party, or PAN) for a coalition between the PAN and the leftist Party of the Democratic Revolution (PRD); and Margarita Zavala, wife of former President Felipe Calderón, as an independent. Some observers are concerned that a López Obrador victory could signal a significant change in Mexico's historically investor-friendly policies and cause friction with the United States, but others predict that he would govern pragmatically. U.S. Policy U.S.-Mexican relations remain relatively strong, but periodic tensions have emerged since January 2017. In recent years, both countries have prioritized bolstering economic ties, particularly energy cooperation; interdicting illegal migration from Central America; and combating drug trafficking, including heroin and fentanyl. Security cooperation has continued under the Mérida Initiative, a security partnership for which Congress has provided Mexico some $2.7 billion since FY2008. In January 2017, President Trump's assertion that Mexico should pay for a border wall that it has consistently opposed led Peña Nieto to cancel a White House visit. Although the Mexican government continues to oppose paying for the border wall and is concerned about the future of the Deferred Action for Childhood Arrivals (DACA) initiative, which has shielded some 550,000 Mexicans from deportation, bilateral security and migration management efforts continue. The Trump Administration requested $85 million for the Mérida Initiative for FY2018 (a 35% decline from FY2017). Mexican leaders are preparing for a possible U.S. withdrawal from NAFTA, which could severely impact the Mexican economy, although renegotiations continue. Legislative Action The 115th Congress has considered legislation affecting Mexico in FY2017 and FY2018, focused largely on cooperative border security, combating crime and drug smuggling.